I've been a fair-to-middling Maroney backer, and certainly an opponent of the "draft McFadden" school.
When Maroney is called upon to play the "featured back" role he passes with flying colors. He gets the job done. Yesterday was a good example. We needed that role. He played that role. He got it done. My guess is that since he's got a 4+ yard per carry average, and he maintains it when you feed him the ball 20-25 times, the only way he can "repeat the performance" over and over is to kick Faulk to the curb, stop passing so much, and consider the remainder of the year an experiment in making a few fantasy football players happy. I'd say the jury is still out on those 20-25 carry games, since our data set is small, but there is no real reason to think he can't handle whatever load we assign him.
McFadden, on the other hand, despite his "blue chip" aura, made all those nifty YouTube highlight reels against college teams. I can not emphasize this enough. He has never played a down in the NFL. This represents risk. You can not compare the value of a proven draft bonanza, such as an Adrian Peterson, to an unproven commodity, such as McFadden (any more than you can say authoritatively that he will be a Reggie Bush or a Ron Dayne.)
As to Maroney himself: The one issue that keeps coming up has to do with an "outside running" style in the process of being adapted to the NFL, where precious few teams do a lot of outside running. The poster boy for the draft-day "sure thing," Reggie Bush, illustrates this well. The league just has too much speed on defensive lines and linebacking corps, not to mention safeties. The same holds true inside, of course, but the difference isn't as exaggerated, since inside runs aren't in space.
So: the Patriots, like any NFL club, needs a running game. The evidence is that the Patriots have a running game, when they need one, not that they eschew the run because they have no confidence.
What, then, is the effect of spending a high pick on a running back?
1) You can pay more for a position at which the Pats are well stocked and productive
2) You can take a risk that your high first round bonus baby will totally suck
3) To "buy down" that risk, you can waste an extra roster spot, by keeping the three main productive backs you have, and adding the bonus baby.
So, there is a cost associated with any change. There are risks associated with any change. Naturally, if your running game is unsatisfactory, you must accept the costs and/or risks.
The difficulty with incurring additional risks or costs, is that the running game is not unsatisfactory, unless the expectation is to have a 20-TD back, as well as a 45+-TD passing game.
All else being equal, that's not such a bad idea. But all else is not equal. We can use that high pick to acquire a raft of prospects and/or future picks.
I feel the same way about the trade talk I've seen around here. Again: when have we called on the running game this year and come up empty?
That's what you have to measure performance by, doing what is asked of the player(s) you're talking about.
You always demand more, to push them to get better (and Maroney might have plenty more upside yet.) You never accept less -- and Maroney hasn't given us less. But you don't fix it if it ain't broke.
Unless the running game lost us a game this year that I just don't recall
PFnV